7-33. What happens to the lubricating oil that leaks  past  newly  installed  piston  rings into  a  cylinder? 1. It  drains  into  the  sump 2. It burns in the cylinder 3. It  collects  on  the  piston  crown 4. It  passes  out  of  the  cylinder  into the  exhaust 7-34. An  unbalanced  cylinder  will  cause  which of  the  following  effects? 1. It  will  gum  up  the  combustion  spaces 2. It  will  score  the  cylinder  wall 3. It  will  corrode  the  piston  crown 4. It  will  overheat  the  engine 7-35. Engine  efficiency  is  measured  by  the relationship  between  energy  input  and what  other  factor? 1. Temperature  of  exhaust 2. Amount  of  fuel  consumed 3. Temperature  of  combustion 4. Amount  of  power  developed 7-36. Compression ratio refers to the relation between  the  volume  of  air  above  a  piston when it is at top dead center and what other  factor? 1. The  volume  of  air  below  the  piston when it is at top dead center 2. The  volume  of  air  above  the  piston when it is at bottom dead center 3. The  pressure  of  the  air  above  the piston when it is at top dead center 4. The  temperature  of  the  air  below  the piston when it is at bottom dead center 7-37. Why  is  the  efficiency  of  the  Otto  cycle less  than  that  of  the  diesel  cycle? 1. Because  the  Otto  cycle  reaches  a higher   temperature 2. Because  the  Otto  cycle  has  a  lower compression   ratio 3. Because  the  Otto  cycle  uses  a greater  amount  of  air 4. Because  the  Otto  cycle  uses  a  smaller amount  of  air 7-38. Assume  that  an  engine  has  an  indicated horsepower  of  1,600  and  uses  400  pounds of fuel per hour. If the fuel has a value  of  20,000  Btu  per  pound,  what  is the  indicated  thermal  efficiency  of  the engine? 1. 40.9% 2. 49.4% 3. 50.9% 4. 53.2% 7-39. If an engine consumes 70 pounds of fuel in an hour and the fuel has a potential energy  of  20,000  Btu  per  pound,  what  is the  potential  power  of  the  engine?  (Use the factor of 2545 Btu per hr/hp.) 1. 36.4 hp 2. 55.0 hp 3. 363.6 hp 4. 550.1 hp 7-40. The  overall  thermal  efficiency  of  an engine is 50 percent and the brake horse- power  is  1,450.00  Btu  per  hour. What  is the value of the heat input of fuel? 1. 725,000 Btu per hr 2. 1,450,000 Btu per hr 3. 2,000,000 Btu per hr 4. 2,900,000 Btu per hr 7-41. Which  of  the  following  factors  has  the greatest  effect  on  the  mechanical efficiency  of  an  engine? 1. Vaporization 2. Corrosion 3. Friction 4. Combustion 7-4 2. What  is  the  relationship  between  the amount  of  friction  between  the  moving parts of an engine and the speed of the engine? 1. Friction  increases  at  high  speeds 2. Friction  decreases  at  low  speeds 3. Friction  remains  constant  throughout the  speed  range 4. Friction  increases  at  low  speeds  and decreases  at  high  speeds Information  for  questions  7-43  through 7-53: A 6-cylinder, single-acting, 2-stroke  cycle,  diesel  engine  has  a  mean effective  pressure  of  104  psi  per  cylinder when  operating  at  full  load  and  rated  speed  of 2,500 rpm. The stroke and cylinder bore are 5 inches and 4 inches, respectively. The engine's frictional  horsepower  is  32  hp  and  does  not change with changes in load or speed. At 2,000 rpm,  the  brake  horsepower  for  the  engine  is  166 hp. 45